Marc Levy is associate director for science applications at the Center for International Earth Science Information Network (CIESIN), which was established in 1989 as an independent nongovernmental organization (NGO) providing information to help scientists, decision-makers and the general public better understand the changing relationship between human beings and the environment.

In 1998, CIESIN became a center within Columbia University's Earth Institute. From its offices at Columbia's Lamont-Doherty Earth Observatory campus in Palisades, N.Y., CIESIN continues to focus on applying advanced information technologies to pressing interdisciplinary data, information and research problems related to human interactions in the environment. CIESIN was one of the first organizations involved in developing and providing interactive data access and mapping tools via the Internet. Given the great diversity of scientific data and information resources now available, CIESIN continues to implement innovative approaches to data identification, access, visualization and analysis across distributed data systems.

Q: Perhaps the best place to start is talking a little about CIESIN itself.

A: CIESIN's main mission is to promote better understanding of interaction between humans and their environment. We have a strong emphasis on information and data systems that strengthen the empirical foundation of our understanding and ability to make decisions about the way humans and the environment interact. We have a strong emphasis on GIS. We work a lot with spatial data, and in general, try to put things in a spatial context.

Some of the most prominent work we've done on sustainability centers around our work with environmental sustainability. Even though that was an effort to compare countries, I think experience is relevant to a lot of your readers. The impetus for the work was to see if all the talk about sustainable development could be made more concrete by assembling and publishing an actual quantitative index of environmental sustainability -- one that would compare countries in a more or less robust, empirical fashion.

The work was sponsored by the World Economic Forum, which has an annual meeting where dignitaries, heads of state, industry leaders and members of the press get together. So that forum got the work lots of attention, and we have put out three consecutive years of sustainability index.

Q: What did you discover as a result of this work?

A: We found out two things, speaking generally. First, there was a strong demand for a better quantitative metric to make sustainability more tangible and more concretely understandable. Second, the data available to make this kind of comparison was not as good as people would like.

It is a bit of a mixed message. On one hand, people welcomed the assembly of a collection of databases that could put numbers on what was otherwise a pretty vague subject. On the other hand, it illuminated how deficient we were at collecting data that would make firm conclusions about how close we are to achieving sustainability. Or in which particular areas we are the most far off.

Q: Essentially you are trying to answer for governments and world leaders, "How big of a situation is sustainability?"

A: Yes, I think it's easy for politicians or anybody to get away with fairly empty rhetoric if there is no alternative information source that lets people compare rhetoric to reality. The idea of publishing databases and indexes is meant to empower people across all sectors of society, so they can be more focused and real about this. Many different sectors use our index -- governments, international agencies, NGOs, think tanks and so on. What all these have in common is they want to zero in on what's really happening. They want to move beyond simply talking about things to understanding what's happening.

I have been following the sustainability debate at the state and local